xref: /illumos-gate/usr/src/lib/libc/port/gen/fdopendir.c (revision 4eaa471005973e11a6110b69fe990530b3b95a38)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 /*
30  * fdopendir, dirfd -- C library extension routines
31  *
32  * We use lmalloc()/lfree() rather than malloc()/free() in
33  * order to allow opendir()/readdir()/closedir() to be called
34  * while holding internal libc locks.
35  */
36 
37 #pragma weak _fdopendir = fdopendir
38 
39 #include "lint.h"
40 #include <mtlib.h>
41 #include <dirent.h>
42 #include <sys/stat.h>
43 #include <fcntl.h>
44 #include <stdlib.h>
45 #include <unistd.h>
46 #include <errno.h>
47 #include "libc.h"
48 
49 DIR *
50 fdopendir(int fd)
51 {
52 	private_DIR *pdirp = lmalloc(sizeof (*pdirp));
53 	DIR *dirp = (DIR *)pdirp;
54 	void *buf = lmalloc(DIRBUF);
55 	int error = 0;
56 	struct stat64 sbuf;
57 
58 	if (pdirp == NULL || buf == NULL)
59 		goto fail;
60 	/*
61 	 * POSIX mandated behavior
62 	 * close on exec if using file descriptor
63 	 */
64 	if (fcntl(fd, F_SETFD, FD_CLOEXEC) < 0)
65 		goto fail;
66 	if (fstat64(fd, &sbuf) < 0)
67 		goto fail;
68 	if ((sbuf.st_mode & S_IFMT) != S_IFDIR) {
69 		error = ENOTDIR;
70 		goto fail;
71 	}
72 	dirp->dd_buf = buf;
73 	dirp->dd_fd = fd;
74 	dirp->dd_loc = 0;
75 	dirp->dd_size = 0;
76 	(void) mutex_init(&pdirp->dd_lock, USYNC_THREAD, NULL);
77 	return (dirp);
78 
79 fail:
80 	if (pdirp != NULL)
81 		lfree(pdirp, sizeof (*pdirp));
82 	if (buf != NULL)
83 		lfree(buf, DIRBUF);
84 	if (error)
85 		errno = error;
86 	return (NULL);
87 }
88 
89 int
90 dirfd(DIR *dirp)
91 {
92 	return (dirp->dd_fd);
93 }
94